General Antonyms:
* Artificial: This is the most common and general antonym, referring to something made or produced by humans rather than occurring naturally.
* Unnatural: This word implies something that goes against the natural order of things or is unusual.
* Synthetic: This term refers specifically to something made by chemical processes, as opposed to natural substances.
* Man-made: This emphasizes the human origin of something.
Specific Antonyms Depending on Context:
* Fake: This implies something that is not genuine or authentic.
* Cultivated: This contrasts with something that occurs naturally in the wild.
* Manufactured: This refers to something that is produced in a factory or industrial setting.
* Unrefined: This is the opposite of something that is natural and refined, like a natural diamond versus a polished diamond.
Other Antonyms:
* Supernatural: This refers to something that is beyond the natural world, like magic or spirits.
* Abnormal: This implies something that deviates from the normal or expected.
To determine the best antonym for "natural," it's important to consider the specific context in which you are using the word.